Species differences in brain acetylcholinesterase and neuropathic target esterase response to monocrotophos.

The species differences in the neurotoxic and delayed neurotoxic potential of monocrotophos (MCP) were assessed by determining the in vitro inhibition of brain Acetylcholinesterase (AChE) and Neuropathic target esterase (NTE) in rat, mice, chicken and pigeon. Based on I50 values, chicken brain AChE was found to be most sensitive to inhibition by MCP followed by rat whereas mice and pigeon were almost equally sensitive to AChE inhibition by MCP. The data on NTE inhibition by MCP in all the four species indicate the non-delayed neurotoxic nature of MCP. The results show that although there are many common features of the brain AChE and NTE of the four non-target organisms studied, certain species characteristics exist in their inhibition responses to MCP.